Table 1.

Clinical trial vignettes describing 3 hypothetical trials and response scale for assessment of primary outcome.

Diet Vignette
Suppose you are overweight. You are asked to volunteer for a study looking at how well a new diet may help people lose weight. Half of the people who join the study will be placed on the new diet. The other half will be placed on a more standard diet for weight loss (for example Weight Watchers). The two groups will then be compared to one another. Your participation should not inconvenience you or increase the costs of your meals at home.
Hypertension Vignette
Suppose that you are newly diagnosed with high blood pressure. You are asked to volunteer for a study looking at how well a new pill treats high blood pressure. Half of the people who join the study will take the new pill. The other half will take a commonly used pill. The two groups will then be compared to one another. You won’t know which type of pill you received until the trial is over. The new pill is not expected to cause side effects.
Cancer Vignette
Suppose you have been diagnosed with a life-threatening cancer. You are asked to volunteer for a study looking at a new treatment for cancer. Half of the people who join the study will take the new treatment while the other half will receive usual care. The two groups will then be compared to one another. You won’t know which treatment you received until the trial is over. Both types of treatment might cause side effects such as nausea.
How Willing would you be to participate in this clinical research trial?
Response Scale a
Not willing		Somewhat willing		Very willing
1	2	3	4	5

^aResponses dichotomized into categories of “willing to participate” (responses 4 or 5) and “unwilling to participate” (responses 1, 2, or 3)